US registration reviews

Date:03-31-2008

The US EPA has issued preliminary work plans for a further seven pesticides entering the registration review programme. The Agency has opened public dockets for: the herbicides, acetic acid and glufosinate-ammounium; the insecticide/fungicide, silica; the fungicides and/or fumigants, sulfur, carbon dioxide and nitrates/nitrites; and the fungicide/bactericide, propionic acid. The reviews are due to be completed in 2-5 years.

Acetic acid is used as a non-selective herbicide for grass and broadleaf weed control as well as a preservative for stored grains. The review case also includes the acetic acid salt, sodium diacetate, which is a fungicide and bactericide. The EPA plans to conduct a comprehensive ecological risk assessment for the herbicide use of acetic acid. It will also conduct an endangered species asssessment for all pesticide uses of acetic acid and sodium diacetate. No further human health risk assessments are likely. The review is due for completion in 2012.

Bayer CropScience's non-selective herbicide, glufosinate-ammonium, is registered for use on a range of crops and a variety of non-crop applications. The EPA expects to conduct comprehensive human health and ecological risk assessments for all uses. It has concerns over risks to non-target plants and chronic risks to mammals, with potential indirect effects on animals due to alterations in aquatic plant communities. The Agency expects to make revisions to dietary, residential, occupational and aggregate risk assessments for glufosinate-ammonium pending the consideration of data submitted since its 2003 assessments. Additional data may also be required. The review should be completed in 2013.

The silica review case covers silicon dioxide and silica gel, which are used to control insects and fungi by desiccation on crops and stored grain. The EPA will conduct a comprehensive ecological risk assessment, including an endangered species assessment, for all uses. The 1991 re-registration eligibility decision concluded that silicon dioxide and silica gel were "practically non-toxic" to non-target organisms, the Agency points out. No revisions to the human health risk assessment are expected. The review is due for completion in 2013.

Sulfur is registered for use as a fungicide and insecticide on a range of crops. It is also used in combination with carbon dioxide and inorganic nitrates/nitrites as a fumigant for the control of certain mammals. The EPA expects to conduct an ecological risk assessment, including an endangered species assessment, for these fumigant uses. New occupational and residential exposure assessments will be required for all uses of sulfur. The carbon dioxide and nitrate/nitrite reviews are due to be completed in 2010, while the sulfur case is schedule for completion in 2013.

Propionic acid is used as a fungicide/bactericide on stored hay and grain and on livestock feed. The EPA does not expect to conduct ecological or human health risk assessments, but an endangered species assessment will be carried out. The review is due for completion in 2011.